Penny Stain: How to Make

I was excited about trying the vinegar and pennies and followed the directions from your article, but nothing happened. The pennies have been soaking for about 2 weeks now and for the most part the vinegar is still clear. What am i doing wrong? Laura

Answers

When making a stain using vinegar and a metal object there needs to be an introduction of oxygen. I just made the penny stain in under an hour. Add hydrogen peroxide to the vinegar. The results with the pennies weren't instant, but it developed pretty quickly, as did the stains I made with steel wool and the other with rusty nails. I really hope this helps!

I want to discuss 2 items both address in other answers. First copper, pennies before 1964 are not pure copper. Second acidity, add a little salt to the mix and the effective acidity will be increased (lemon juice or vinegar either will work).